Blog
About

160
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Role of natural convection in the dissolution of sessile droplets

      Preprint

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          The dissolution process of small (initial (equivalent) radius \(R_0 < 1\) mm) long-chain alcohol (of various types) sessile droplets in water is studied, disentangling diffusive and convective contributions. The latter can arise for high solubilities of the alcohol, as the density of the alcohol-water mixture is then considerably less as that of pure water, giving rise to buoyancy driven convection. The convective flow around the droplets is measured, using micro-particle image velocimetry (\(\mu\)PIV) and the schlieren technique. When nondimensionalizing the system, we fnd a universal \(Sh\sim Ra^1/4\) scaling relation for all alcohols (of different solubilities) and all droplets in the convective regime. Here Sh is the Sherwood number (dimensionless mass flux) and Ra the Rayleigh number (dimensionless density difference between clean and alcohol-saturated water). This scaling implies the scaling relation \(\tau_c \sim R^5/4\) of the convective dissolution time \(\tau_c\), which is found to agree with experimental data. We show that in the convective regime the plume Reynolds number (the dimensionless velocity) of the detaching alcohol-saturated plume follows \(Re_p \sim Sc^-1 Ra^5/8\), which is confirmed by the \(\mu\)PIV data. Here, Sc is the Schmidt number. The convective regime exists when \(Ra > Ra_t\), where \(Ra_t = 12\) is the transition Ra-number as extracted from the data. For \(Ra < Ra_t\) and smaller, convective transport is progressively overtaken by diffusion and the above scaling relations break down.

          Related collections

          Most cited references 16

          • Record: found
          • Abstract: not found
          • Article: not found

          On the Stability of Gas Bubbles in Liquid‐Gas Solutions

            Bookmark
            • Record: found
            • Abstract: not found
            • Article: not found

            Evaporation of a Sessile Droplet on a Substrate

             Hua Hu,  Ronald Larson (2002)
              Bookmark
              • Record: found
              • Abstract: not found
              • Article: not found

              The evaporation of sessile or pendant drops in still air

               R.G Picknett,  R Bexon (1977)
                Bookmark

                Author and article information

                Journal
                1601.05226
                10.1017/jfm.2016.158

                Thermal physics & Statistical mechanics

                Comments

                Comment on this article